Apparatus for encoding and decoding of integrated speech and audio
Provided is an encoding apparatus for integrally encoding and decoding a speech signal and a audio signal, and may include: an input signal analyzer to analyze a characteristic of an input signal; a stereo encoder to down mix the input signal to a mono signal when the input signal is a stereo signal, and to extract stereo sound image information; a frequency band expander to expand a frequency band of the input signal; a sampling rate converter to convert a sampling rate; a speech signal encoder to encode the input signal using a speech encoding module when the input signal is a speech characteristics signal; a audio signal encoder to encode the input signal using a audio encoding module when the input signal is a audio characteristic signal; and a bitstream generator to generate a bitstream.
1. An encoding method of an input signal, the encoding method comprising:
by at least one processor:
analyzing at least one characteristic of the input signal comprising a plurality of frames to determine whether a frame among the plurality of frames of the input signal is a speech frame having a speech characteristic or an audio frame having an audio characteristic;
encoding a core band of the input signal by:
selecting a speech encoder in response to the determination that the frame is the speech frame, and
selecting an audio encoder in response to the determination that the frame is the audio frame; and
generating a bitstream based on the encoded core band of the input signal,
wherein the generated bitstream includes information for compensating at least one change of a frame unit between the speech frame and the audio frame when a switching occurs between the speech frame and the audio frame in a decoding process about the input signal,
wherein the core band is a low frequency band which is not expanded in a frequency band of the input signal, and
wherein a high frequency band is generated using the core band based on a frequency band expander in a decoding process.
2. The encoding method of claim 1 , further comprising:
converting a sampling rate of the input signal having an expanded frequency band to a sampling rate for the encoding the core band of the input signal.
3. The encoding method of claim 2 , wherein the converting comprises:
converting the sampling rate of the input signal to a sampling rate required by one of the speech encoder and the audio encoder.
4. The encoding method of claim 2 , wherein the converting comprises:
down-sampling the sampling rate of the input signal by one half (½).
5. The encoding method of claim 2 , wherein the converting comprises:
down-sampling the sampling rate of the input signal by one quarter (¼).
6. The encoding method of claim 1 , wherein the audio encoder is an advanced audio coding (AAC)-based encoder.
7. The encoding method of claim 1 , wherein the speech encoder is an Adaptive Multi-Rate Wideband Plus (AMR-WB+) or Code Excitation Linear Prediction (CELP) based encoder.
8. The encoding method of claim 1 , wherein, while the input signal changes between the speech frame and the audio frame during the decoding, the information for compensating at least one change of the frame unit between the speech frame and the audio frame includes an encoded portion of the speech frame of the input signal for decoding the audio frame of the input signal.
9. A decoding method for an encoded input signal, the decoding method comprising:
by at least one processor:
analyzing at least one characteristic of the encoded input signal comprising a plurality of frames to determine whether a frame among the plurality of frames of the encoded input signal is a speech frame having a speech characteristic or an audio frame having an audio characteristic;
decoding the encoded input signal by decoding a core band of the encoded input signal from a bitstream signal by:
selecting a speech decoder in response to the determination that the frame is the speech frame, and
selecting an audio decoder in response to the determination that the frame is the audio frame,
wherein the input signal is processed by using information for compensating a change of a frame unit between the speech frame and the audio frame when a switching occurs between the speech frame and the audio frame in a decoding process about the input signal,
wherein the core band of the encoded input signal includes a low frequency band other than a high frequency band expanded in a frequency band of an input signal,
wherein the core band is a low frequency band which is not expanded in a frequency band of the input signal, and
wherein a high frequency band is generated using the core band based on a frequency band expander in a decoding process.
10. The decoding method of claim 9 , further comprising:
converting a sampling rate of the decoded input signal to a sampling rate of the input signal before being encoded.
11. The decoding method of claim 10 , wherein the converting comprises:
up-sampling the sampling rate of the decoded input signal by 2 to the sampling rate of the input signal before being encoded.
12. The decoding method of claim 10 , wherein the converting comprises:
up-sampling the sampling rate of the decoded input signal by 4 to the sampling rate of the input signal before being encoded.
13. The decoding method of claim 10 , wherein, while the converting is performed on the decoded input signal including the speech frame and the audio frame, conversion information for compensating the decoded input signal includes an encoded portion of the speech frame of the input signal for decoding the audio frame of the input signal.
14. A decoding method for an encoded input signal, comprising:
by at least one processor:
analyzing at least one characteristic of the encoded input signal comprising a plurality of bit stream signals to determine whether a bit stream signal among the plurality of bit stream signals is associated with a speech characteristic signal or an audio characteristic signal;
decoding a core band of the encoded input signal from the bit stream signal by a speech decoder in response to the determination that the bitstream signal is associated with the speech characteristic signal; and
decoding the core band of the encoded input signal from the bitstream signal by an audio decoder in response to the determination the bitstream signal is associated with the audio characteristic signal,
wherein the core band is a low frequency band which is not expanded in a frequency band of the input signal,
wherein a high frequency band is generated using the core band based on a frequency band expander in a decoding process, and
wherein the input signal is processed by using information for compensating a change of a frame unit between the speech frame and the audio frame when a switching occurs between the speech frame and the audio frame in a decoding process about the input signal.
15. A decoding method for an encoded input signal, comprising:
by at least one processor:
analyzing at least one characteristic of the encoded input signal comprising a plurality of frames to determine whether each of the plurality of frames is associated with a speech characteristic signal or an audio characteristic signal;
decoding frames associated with the speech characteristic signal among the plurality of frame of the encoded input signal by a speech decoder; and
decoding frames associated with the audio characteristic signal of the encoded input signal by an audio decoder; and
wherein the frames associated with the speech characteristic signal and the frames associated with the audio characteristic signal are decoded in a core band of the decoded input signal,
wherein the core band is a low frequency band which is not expanded in a frequency band of the input signal,
wherein a high frequency band is generated using the core band based on a frequency band expander in a decoding process, and
wherein the input signal is processed by using information for compensating a change of a frame unit between the speech frame and the audio frame when a switching occurs between the speech frame and the audio frame in a decoding process about the input signal.